71-581: The Pacific Time Zone ( PT ) is a time zone encompassing parts of western Canada, the western United States, and western Mexico. Places in this zone observe standard time by subtracting eight hours from Coordinated Universal Time ( UTC−08:00 ). During daylight saving time , a time offset of UTC−07:00 is used. In the United States and Canada, this time zone is generically called the Pacific Time Zone. Specifically, time in this zone
142-596: A 2018 ballot proposition that authorizes the legislature to use year-round daylight time, pending Congressional approval. The Washington State Legislature passed a bill in May 2019 that would move the state to permanent daylight time, subject to Congressional approval; the Oregon Legislative Assembly passed a similar bill a month later, while California's attempt failed. The provincial government of British Columbia announced in 2019 that they would follow
213-426: A 30-minute offset. Nepal was the last country to adopt a standard offset, shifting slightly to UTC+05:45 in 1986. All nations currently use standard time zones for secular purposes, but not all of them apply the concept as originally conceived. Several countries and subdivisions use half-hour or quarter-hour deviations from standard time. Some countries, such as China and India , use a single time zone even though
284-564: A C library based on the BSD C library, or the System V Release 4 C library, can make use of this database. Windows -based computer systems prior to Windows 95 and Windows NT used local time, but Windows 95 and later, and Windows NT, base system time on UTC. They allow a program to fetch the system time as UTC, represented as a year, month, day, hour, minute, second, and millisecond; Windows 95 and later, and Windows NT 3.5 and later, also allow
355-574: A May 1915 ordinance settled on EST and was ratified by popular vote in August 1916. The confusion of times came to an end when standard time zones were formally adopted by the U.S. Congress in the Standard Time Act of March 19, 1918. Italian mathematician Quirico Filopanti introduced the idea of a worldwide system of time zones in his book Miranda! , published in 1858. He proposed 24 hourly time zones, which he called "longitudinal days",
426-480: A clock for each railroad, each showing a different time. Because of this a number of accidents occurred when trains from different companies using the same tracks mistimed their passings. Around 1863, Charles F. Dowd proposed a system of hourly standard time zones for North American railroads, although he published nothing on the matter at that time and did not consult railroad officials until 1869. In 1870 he proposed four ideal time zones having north–south borders,
497-444: A convenient time, usually at night, not exactly when they cross a certain longitude. Some ships simply remain on the time of the departing port during the whole trip. Ideal time zones, such as nautical time zones, are based on the mean solar time of a particular meridian in the middle of that zone with boundaries located 7.5 degrees east and west of the meridian. In practice, however, many time zone boundaries are drawn much farther to
568-744: A standard reference time while each location in England kept a different time. In the 19th century, as transportation and telecommunications improved, it became increasingly inconvenient for each location to observe its own solar time. In November 1840, the British Great Western Railway started using GMT kept by portable chronometers . This practice was soon followed by other railway companies in Great Britain and became known as railway time . Around August 23, 1852, time signals were first transmitted by telegraph from
639-479: A standard time zone, but only some of them used an hourly offset from GMT. Many applied the time at a local astronomical observatory to an entire country, without any reference to GMT. It took many decades before all time zones were based on some standard offset from GMT or Coordinated Universal Time (UTC). By 1929, the majority of countries had adopted hourly time zones, though some countries such as Iran , India , Myanmar and parts of Australia had time zones with
710-430: A two-year experiment from January 6, 1974, to April 7, 1975, but Congress later ended the experiment early on October 27, 1974, and did not make it permanent due to unfavorable public opinion, especially regarding concerns about children walking to school and waiting for school buses on dark winter mornings. In the late 2010s, resolutions were passed in more than 30 states advocating for the federal government to abolish
781-461: A whole number of hours, but a few zones are offset by an additional 30 or 45 minutes, such as in India and Nepal . Some areas in a time zone may use a different offset for part of the year, typically one hour ahead during spring and summer , a practice known as daylight saving time (DST). In the table below, the locations that use daylight saving time (DST) are listed in their UTC offset when DST
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#1732765297248852-605: A year later due to protests by farmers. Many states subsequently introduced daylight saving time, and in 1966, the Uniform Time Act standardized the dates when it begins and ends. Hawaii, most of Arizona, and the U.S. territories have opted to observe permanent standard time , but the Uniform Time Act forbids observation of permanent daylight saving time. The Emergency Daylight Saving Time Energy Conservation Act enacted year-round daylight saving time for
923-567: Is not in effect. When DST is in effect, approximately during spring and summer, their UTC offset is increased by one hour (except for Lord Howe Island , where it is increased by 30 minutes). For example, during the DST period California observes UTC−07:00 and the United Kingdom observes UTC+01:00 . The apparent position of the Sun in the sky, and thus solar time , varies by location due to
994-407: Is 11 hours 30 minutes ahead of GMT. This standard was known as New Zealand Mean Time . Timekeeping on North American railroads in the 19th century was complex. Each railroad used its own standard time, usually based on the local time of its headquarters or most important terminus, and the railroad's train schedules were published using its own time. Some junctions served by several railroads had
1065-628: Is a standard established by the International Organization for Standardization defining methods of representing dates and times in textual form, including specifications for representing time zones. If a time is in Coordinated Universal Time (UTC), a "Z" is added directly after the time without a separating space. "Z" is the zone designator for the zero UTC offset. "09:30 UTC" is therefore represented as "09:30Z" or "0930Z". Likewise, "14:45:15 UTC"
1136-470: Is an area which observes a uniform standard time for legal , commercial and social purposes. Time zones tend to follow the boundaries between countries and their subdivisions instead of strictly following longitude , because it is convenient for areas in frequent communication to keep the same time. Each time zone is defined by a standard offset from Coordinated Universal Time (UTC). The offsets range from UTC−12:00 to UTC+14:00 , and are usually
1207-629: Is appended to local times in the same way that alphabetic time zone abbreviations (or "Z", as above) are appended. The offset from UTC changes with daylight saving time , e.g. a time offset in Chicago , which is in the North American Central Time Zone , is " −06:00 " for the winter (Central Standard Time) and " −05:00 " for the summer (Central Daylight Time). Time zones are often represented by alphabetic abbreviations such as "EST", "WST", and "CST", but these are not part of
1278-476: Is referred to as Pacific Standard Time (PST) when standard time is being observed (early November to mid-March), and Pacific Daylight Time (PDT) when daylight saving time (mid-March to early November) is being observed. In Mexico , the corresponding time zone is known as the Zona Noroeste (Northwest Zone) and observes the same daylight saving schedule as the United States and Canada. The largest city in
1349-640: Is split between the Pacific Time Zone and the Mountain Time Zone: The border between time zones in British Columbia was decided in a 1972 plebiscite held in northeastern and southeastern electoral districts due to their ties to neighboring Alberta . As of September 24, 2020, Yukon officially switched from the Pacific Time Zone to a time zone "to be reckoned as seven hours behind Coordinated Universal Time (UTC−7)" after deciding to stop observing daylight saving time. In Mexico ,
1420-430: Is that the change itself causes most of the negative effects, more so than either standard time or daylight saving time. Researchers have observed numerous ill effects of the annual transitions, including reduced worker productivity, increased heart attacks and strokes , increased medical errors , and increased traffic incidents . The debate over the bill mainly concerns whether it is better to have more sunlight in
1491-467: Is to allow the more efficient use of afternoon sunlight. Some of these locations also use daylight saving time (DST), further increasing the difference to local solar time. As a result, in summer, solar noon in the Spanish city of Vigo occurs at 14:41 clock time. This westernmost area of continental Spain never experiences sunset before 18:00 clock time, even in winter, despite lying 42 degrees north of
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#17327652972481562-505: Is too benign or obviously doomed to bother their boss with." BuzzFeed identified Tom Cotton ( R‑AR ) as a senator who, according to a member of his staff, was vehemently opposed to the bill and would have objected to its passage had he been informed of it. Upon being passed by the Senate, the bill faced uncertain prospects in the House. Ultimately, the 117th Congress ended without
1633-599: Is updated whenever time zone or daylight saving time rules change. Oracle provides an updater tool for this purpose. As an alternative to the information bundled with the Java Platform, programmers may choose to use the Joda-Time library. This library includes its own data based on the IANA time zone database. As of Java 8 there is a new date and time API that can help with converting times. Traditionally, there
1704-403: Is usually converted to local time when displayed to the user, and times specified by the user in local time are converted to Unix time. The conversion takes into account the time zone and daylight saving time rules; by default the time zone and daylight saving time rules are set up when the system is configured, though individual processes can specify time zones and daylight saving time rules using
1775-533: Is written as "14:45:15Z" or "144515Z". UTC time is also known as "Zulu" time, since "Zulu" is a phonetic alphabet code word for the letter "Z". Offsets from UTC are written in the format ±hh:mm, ±hhmm, or ±hh (either hours ahead or behind UTC). For example, if the time being described is one hour ahead of UTC (such as the time in Germany during the winter), the zone designator would be " +01:00 ", "+0100", or simply "+01". This numeric representation of time zones
1846-544: The IANA time zone database and includes the ability to get, set and convert between time zones. The DateTime objects and related functions have been compiled into the PHP core since 5.2. This includes the ability to get and set the default script time zone, and DateTime is aware of its own time zone internally. PHP.net provides extensive documentation on this. As noted there, the most current time zone database can be implemented via
1917-506: The PECL timezonedb. Sunshine Protection Act The Sunshine Protection Act is a proposed United States federal law that would make U.S. daylight saving time permanent, meaning the time would no longer change twice per year. The bill has been proposed during several sessions of Congress. In 2022, the Senate passed the bill by unanimous consent, although several senators stated later that they would have objected if they had known that
1988-513: The TZ environment variable . This allows users in multiple time zones, or in the same time zone but with different daylight saving time rules, to use the same computer, with their respective local times displayed correctly to each user. Time zone and daylight saving time rule information most commonly comes from the IANA time zone database . In fact, many systems, including anything using the GNU C Library ,
2059-810: The Zona Noroeste , which corresponds to Pacific Time in the United States and Canada, includes: Two states are fully contained in the Pacific Time Zone: Three states are split between the Pacific Time Zone and the Mountain Time Zone : One state is split between the Pacific Time Zone (unofficially), the Alaska Time Zone , and the Hawaii–Aleutian Time Zone : Through 2006, the local time (PST, UTC−08:00) changed to daylight time (PDT, UTC−07:00) at 02:00 LST (local standard time) to 03:00 LDT (local daylight time) on
2130-416: The high seas . As an ideal form of the terrestrial time zone system, nautical time zones consist of gores of 15° offset from GMT by a whole number of hours. A nautical date line follows the 180th meridian, bisecting one 15° gore into two 7.5° gores that differ from GMT by ±12 hours. However, in practice each ship may choose what time to observe at each location. Ships may decide to adjust their clocks at
2201-624: The spherical shape of the Earth. This variation corresponds to four minutes of time for every degree of longitude , so for example when it is solar noon in London , it is about 10 minutes before solar noon in Bristol , which is about 2.5 degrees to the west. The Royal Observatory, Greenwich , founded in 1675, established Greenwich Mean Time (GMT), the mean solar time at that location, as an aid to mariners to determine longitude at sea, providing
Pacific Time Zone - Misplaced Pages Continue
2272-420: The House voting on the bill. A 2023 bill has been introduced, but is at a standstill for the time being. As of March 25, 2024 , the full history is as follows: Numerous polls have found that most Americans believe that a standard time should be fixed and permanent—as many as 75% favor no longer changing clocks twice per year. One of the most common observations among researchers of varying backgrounds
2343-710: The New England states). It is hypothesized closer harmony between standard time and biology contributes to safer morning commutes, improved student welfare, practicability of certain religious practices (such as in Orthodox Judaism and Islam ), increased exposure to healthy morning sunlight, and higher productivity and wages. However, advocates of permanent daylight saving time argue it has its own benefits including decreased crime, less frequent traffic incidents, longer evening outdoor recreation and decreased prevalence of seasonal depression . Research
2414-613: The Pacific Time Zone is Los Angeles , whose metropolitan area is also the largest in the time zone. The zone is two hours ahead of the Hawaii–Aleutian Time Zone , one hour ahead of the Alaska Time Zone , one hour behind the Mountain Time Zone , two hours behind the Central Time Zone , three hours behind the Eastern Time Zone , and four hours behind the Atlantic Time Zone . One Canadian province
2485-578: The Royal Observatory. By 1855, 98% of Great Britain's public clocks were using GMT, but it was not made the island's legal time until August 2, 1880. Some British clocks from this period have two minute hands, one for the local time and one for GMT. On November 2, 1868, the British Colony of New Zealand officially adopted a standard time to be observed throughout the colony. It was based on longitude 172°30′ east of Greenwich , that
2556-431: The Senate by unanimous consent on March 15, 2022. Two days later, BuzzFeed News reported that many senators were not aware that a request had been made for the bill to pass via unanimous consent and were not ready to raise an objection. Rubio's office had notified every other senator's office of the request; however, it is a frequent occurrence for legislative staff to "vet the request" themselves to "decide if an issue
2627-595: The Terminal Server so that users see the correct time for their time zone in their desktop/application sessions. Terminal Services uses the server base time on the Terminal Server and the client time zone information to calculate the time in the session. While most application software will use the underlying operating system for time zone and daylight saving time rule information, the Java Platform , from version 1.3.1, has maintained its own database of time zone and daylight saving time rule information. This database
2698-575: The U.S. Several Mexican states, including Baja California, implemented the new dates for the daylight time changes in 2010, ending a three-year period where cities across the Mexico–United States border had a one-hour difference for two months a year. Proposals to abolish the bi-annual time change and adopt year-round standard time or daylight time gained popularity among U.S. states in the 2010s. 59 percent of voters in California approved
2769-582: The U.S. states in whether the time changes were kept or removed in order to maintain a unified time zone. In 2020, Idaho passed legislation to allow for permanent daylight time for the Pacific Time Zone. Congressional approval was sought through the Sunshine Protection Act , which was submitted several times and passed by the U.S. Senate in 2022, but its equivalent in the House of Representatives failed to pass. Time zone A time zone
2840-534: The US version shows Eastern Time . US Eastern Time and Pacific Time are also used fairly commonly on many US-based English-language websites with global readership. The format is typically based in the W3C Note "datetime". Email systems and other messaging systems ( IRC chat , etc.) time-stamp messages using UTC, or else include the sender's time zone as part of the message, allowing the receiving program to display
2911-500: The Virgin Islands) switch to permanent daylight saving time. The Sunshine Protection Act was first introduced in 2018 by U.S. senator Marco Rubio ( R‑FL ), modeled after a 2018 Florida bill of the same name. U.S. president Donald Trump tweeted that he would be willing to sign it, but it failed to advance. A reintroduction in 2019 by Vern Buchanan ( R‑FL 16th ) similarly failed. The 2021 iteration
Pacific Time Zone - Misplaced Pages Continue
2982-503: The annual transitions. The Sunshine Protection Act would establish a permanent daylight saving time in the U.S. , leading to later sunrises and sunsets during the four months in which most of the U.S. currently observes standard time, resulting in less sunlight in the morning hours and more sunlight in the evening ones. It would not mandate that states and territories that observe permanent standard time (American Samoa, most of Arizona, Guam, Hawaii, Northern Mariana Islands, Puerto Rico, and
3053-506: The area becomes a function of UTC time. The time differences may also result in different dates. For example, when it is 22:00 on Monday in Egypt (UTC+02:00), it is 01:00 on Tuesday in Pakistan (UTC+05:00). The table "Time of day by zone" gives an overview on the time relations between different zones. Since the 1920s, a nautical standard time system has been in operation for ships on
3124-513: The article on daylight saving time for more details on this aspect.) Web servers presenting web pages primarily for an audience in a single time zone or a limited range of time zones typically show times as a local time, perhaps with UTC time in brackets. More internationally oriented websites may show times in UTC only or using an arbitrary time zone. For example, the international English-language version of CNN includes GMT and Hong Kong Time, whereas
3195-469: The begin and end dates of daylight saving time are changed, calendar entries should stay the same in local time, even though they may shift in UTC time. Unix-like systems, including Linux and macOS , keep system time in Unix time format, representing the number of seconds (excluding leap seconds ) that have elapsed since 00:00:00 Coordinated Universal Time (UTC) on Thursday, January 1, 1970. Unix time
3266-408: The bill could pass. No iteration of the bill has passed the House. Time zones were first introduced in the United States in 1883 by railroad companies. In 1918, they were codified into federal law by the Standard Time Act , which also included a provision for nationwide daylight saving time modeled after European laws designed to save energy during World War I , but that component was repealed
3337-549: The calendar events are assumed to take place in the time zone the computer or smartphone was on when creating the event. The event can be shown at the wrong time. For example, if a New Yorker plans to meet someone in Los Angeles at 9 am, and makes a calendar entry at 9 am (which the computer assumes is New York time), the calendar entry will be at 6 am if taking the computer's time zone. Calendaring software must also deal with daylight saving time (DST). If, for political reasons,
3408-450: The economy. However the magnitude of effect in either direction is disputed. This happens partly because standard time aligns with the natural circadian cycle , whereas daylight saving time is an hour ahead. Furthermore, the majority of land within each American time zone is skewed westward, creating sunrises and sunsets that are both artificially late even without Daylight Saving Time. (There are exceptions, such as Long Island and
3479-564: The equation is equivalent to UTC. The conversion equation can be rearranged to For example, the New York Stock Exchange opens at 09:30 ( EST , UTC offset= −05:00). In California ( PST , UTC offset= −08:00) and India ( IST , UTC offset= +05:30), the New York Stock Exchange opens at These calculations become more complicated near the time switch to or from daylight saving time, as the UTC offset for
3550-469: The equator. Near the summer solstice , Vigo has sunset times after 22:00, similar to those of Stockholm , which is in the same time zone and 17 degrees farther north. Stockholm has much earlier sunrises, though. In the United States, the reasons were more historical and business-related. In Midwestern states, like Indiana and Michigan , those living in Indianapolis and Detroit wanted to be on
3621-535: The extent of their territory far exceeds the ideal 15° of longitude for one hour; other countries, such as Spain and Argentina , use standard hour-based offsets, but not necessarily those that would be determined by their geographical location. The consequences, in some areas, can affect the lives of local citizens, and in extreme cases contribute to larger political issues, such as in the western reaches of China. In Russia, which has 11 time zones , two time zones were removed in 2010 and reinstated in 2014. ISO 8601
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#17327652972483692-748: The first Sunday in April, and returned at 02:00 LDT to 01:00 LST on the last Sunday in October. The United States Congress passed the Energy Policy Act of 2005 , which moved the local time changes from PST to PDT to the second Sunday in March and the reversal from PDT to PST to the first Sunday in November. Like other Canadian provinces that observe daylight time , British Columbia adopted the same dates in April 2006, to take effect in March 2007 alongside
3763-573: The first centered on Washington, D.C. , but by 1872 the first was centered on meridian 75° west of Greenwich , with natural borders such as sections of the Appalachian Mountains . Dowd's system was never accepted by North American railroads. Chief meteorologist at the United States Weather Bureau Cleveland Abbe divided the United States into four standard time zones for consistency among
3834-532: The first centred on the meridian of Rome . He also proposed a universal time to be used in astronomy and telegraphy. However, his book attracted no attention until long after his death. Scottish -born Canadian Sir Sandford Fleming proposed a worldwide system of time zones in 1876 - see Sandford Fleming § Inventor of worldwide standard time . The proposal divided the world into twenty-four time zones labeled A-Y (skipping J), each one covering 15 degrees of longitude. All clocks within each zone would be set to
3905-449: The greatest terrestrial time zone difference on Earth, with a 3.5 hour difference between Afghanistan's UTC+4:30 and China's UTC+08:00 . Many countries, and sometimes just certain regions of countries, adopt daylight saving time (DST), also known as summer time, during part of the year. This typically involves advancing clocks by an hour near the start of spring and adjusting back in autumn ("spring forward", "fall back"). Modern DST
3976-416: The international time and date standard ISO 8601 . Such designations can be ambiguous; for example, "CST" can mean (North American) Central Standard Time (UTC−06:00), Cuba Standard Time (UTC−05:00) and China Standard Time (UTC+08:00), and it is also a widely used variant of ACST ( Australian Central Standard Time , UTC+09:30). Conversion between time zones obeys the relationship in which each side of
4047-653: The message's date and time of sending in the recipient's local time. Database records that include a time stamp typically use UTC, especially when the database is part of a system that spans multiple time zones. The use of local time for time-stamping records is not recommended for time zones that implement daylight saving time because once a year there is a one-hour period when local times are ambiguous. Calendar systems nowadays usually tie their time stamps to UTC, and show them differently on computers that are in different time zones. That works when having telephone or internet meetings. It works less well when travelling, because
4118-546: The morning or the evening. A 2023 YouGov poll found that half of Americans supported permanent daylight time, 31% were in favor of permanent standard time, and 19% had no preference or were not sure. Opponents of the Sunshine Protection Act argue permanent standard time would be more beneficial to health and human welfare. Numerous health specialists, safety experts, and research societies consider permanent standard time better for health, safety, schools, and
4189-416: The necessary support for working with all (or almost all) possible local times based on the various time zones. Internally, operating systems typically use UTC as their basic time-keeping standard , while providing services for converting local times to and from UTC, and also the ability to automatically change local time conversions at the start and end of daylight saving time in the various time zones. (See
4260-493: The same meridian but north of the Arctic Circle, has two sunsets on the same day in early August, one shortly after midnight at the start of the day, and the other shortly before midnight at the end of the day. China extends as far west as 73°E , but all parts of it use UTC+08:00 ( 120°E ), so solar "noon" can occur as late as 15:00 in western portions of China such as Xinjiang . The Afghanistan-China border marks
4331-548: The same time as the others, but differed by one hour from those in the neighboring zones. He advocated his system at several international conferences, including the International Meridian Conference , where it received some consideration. The system has not been directly adopted, but some maps divide the world into 24 time zones and assign letters to them, similarly to Fleming's system. By about 1900, almost all inhabited places on Earth had adopted
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#17327652972484402-419: The same time zone as New York to simplify communications and transactions. A more extreme example is Nome, Alaska , which is at 165°24′W longitude – just west of center of the idealized Samoa Time Zone ( 165°W ). Nevertheless, Nome observes Alaska Time ( 135°W ) with DST so it is slightly more than two hours ahead of the sun in winter and over three in summer. Kotzebue, Alaska , also near
4473-465: The system time to be fetched as a count of 100 ns units since 1601-01-01 00:00:00 UTC. The system registry contains time zone information that includes the offset from UTC and rules that indicate the start and end dates for daylight saving in each zone. Interaction with the user normally uses local time, and application software is able to calculate the time in various zones. Terminal Servers allow remote computers to redirect their time zone settings to
4544-527: The time-zone system. It was a version proposed by William F. Allen, the editor of the Traveler's Official Railway Guide . The borders of its time zones ran through railroad stations, often in major cities. For example, the border between its Eastern and Central time zones ran through Detroit , Buffalo , Pittsburgh , Atlanta , and Charleston . It was inaugurated on Sunday, November 18, 1883, also called "The Day of Two Noons", when each railroad station clock
4615-471: The war. Similarly, prior to World War II, the Netherlands observed "Amsterdam Time", which was twenty minutes ahead of Greenwich Mean Time. They were obliged to follow German time during the war, and kept it thereafter. In the mid-1970s the Netherlands, as other European states, began observing daylight saving (summer) time. One reason to draw time zone boundaries far to the west of their ideal meridians
4686-472: The weather stations. In 1879, he published a paper titled Report on Standard Time . In 1883, he convinced North American railroad companies to adopt his time-zone system. In 1884, Britain, which had already adopted its own standard time system for England, Scotland, and Wales, helped gather international consent for global time. In time, the American government, influenced in part by Abbe's 1879 paper, adopted
4757-576: The west, and some countries are located entirely outside their ideal time zones. For example, even though the Prime Meridian (0°) passes through Spain and France , they use the mean solar time of 15 degrees east ( Central European Time ) rather than 0 degrees (Greenwich Mean Time). France previously used GMT, but was switched to CET (Central European Time) during the German occupation of the country during World War II and did not switch back after
4828-457: Was filed in the U.S. House of Representatives by Buchanan on January 4, 2021, and in the U.S. Senate by Rubio on March 9, 2021. The bill received bipartisan support, and was cosponsored in the Senate by James Lankford ( R‑OK ), Roy Blunt ( R‑MO ), Sheldon Whitehouse ( D‑RI ), Ron Wyden , ( D‑OR ); Cindy Hyde-Smith , ( R‑MS ), Rick Scott ( R‑FL ), and Ed Markey ( D‑MA ). It passed
4899-415: Was first proposed in 1907 and was in widespread use in 1916 as a wartime measure aimed at conserving coal . Despite controversy , many countries have used it off and on since then; details vary by location and change occasionally. Countries around the equator usually do not observe daylight saving time, since the seasonal difference in sunlight there is minimal. Many computer operating systems include
4970-502: Was reset as standard-time noon was reached within each time zone. The North American zones were named Intercolonial, Eastern, Central, Mountain, and Pacific. Within a year 85% of all cities with populations over 10,000 (about 200 cities) were using standard time. A notable exception was Detroit (located about halfway between the meridians of Eastern and Central time), which kept local time until 1900, then tried Central Standard Time, local mean time , and Eastern Standard Time (EST) before
5041-669: Was very little in the way of time zone support for JavaScript . Essentially the programmer had to extract the UTC offset by instantiating a time object, getting a GMT time from it, and differencing the two. This does not provide a solution for more complex daylight saving variations, such as divergent DST directions between northern and southern hemispheres. ECMA-402, the standard on Internationalization API for JavaScript, provides ways of formatting Time Zones. However, due to size constraint, some implementations or distributions do not include it. The DateTime object in Perl supports all entries in
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